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1 | ///////////////////////////////////////////////////////////////////////////// | |
2 | // Name: imagtga.cpp | |
3 | // Purpose: wxImage TGA handler | |
4 | // Author: Seth Jackson | |
5 | // CVS-ID: $Id$ | |
6 | // Copyright: (c) 2005 Seth Jackson | |
7 | // Licence: wxWindows licence | |
8 | ///////////////////////////////////////////////////////////////////////////// | |
9 | ||
10 | // ============================================================================ | |
11 | // declarations | |
12 | // ============================================================================ | |
13 | ||
14 | // ---------------------------------------------------------------------------- | |
15 | // headers | |
16 | // ---------------------------------------------------------------------------- | |
17 | ||
18 | // For compilers that support precompilation, includes "wx.h". | |
19 | #include "wx/wxprec.h" | |
20 | ||
21 | #ifdef __BORLANDC__ | |
22 | #pragma hdrstop | |
23 | #endif | |
24 | ||
25 | #if wxUSE_IMAGE && wxUSE_TGA | |
26 | ||
27 | #ifndef WX_PRECOMP | |
28 | #include "wx/palette.h" | |
29 | #endif | |
30 | ||
31 | #include "wx/imagtga.h" | |
32 | #include "wx/log.h" | |
33 | #include "wx/scopeguard.h" | |
34 | ||
35 | // ---------------------------------------------------------------------------- | |
36 | // constants | |
37 | // ---------------------------------------------------------------------------- | |
38 | ||
39 | // TGA error codes. | |
40 | enum | |
41 | { | |
42 | wxTGA_OK, | |
43 | wxTGA_INVFORMAT, | |
44 | wxTGA_MEMERR, | |
45 | wxTGA_IOERR | |
46 | }; | |
47 | ||
48 | // TGA header bytes. | |
49 | enum | |
50 | { | |
51 | HDR_OFFSET = 0, | |
52 | HDR_COLORTYPE = 1, | |
53 | HDR_IMAGETYPE = 2, | |
54 | HDR_PALETTESTART = 3, | |
55 | HDR_PALETTELENGTH = 5, | |
56 | HDR_PALETTEBITS = 7, | |
57 | HDR_XORIGIN = 8, | |
58 | HDR_YORIGIN = 10, | |
59 | HDR_WIDTH = 12, | |
60 | HDR_HEIGHT = 14, | |
61 | HDR_BPP = 16, | |
62 | HDR_ORIENTATION = 17, | |
63 | HDR_SIZE | |
64 | }; | |
65 | ||
66 | // TGA color types. | |
67 | enum | |
68 | { | |
69 | wxTGA_UNMAPPED = 0, | |
70 | wxTGA_MAPPED = 1 | |
71 | }; | |
72 | ||
73 | // ============================================================================ | |
74 | // implementation | |
75 | // ============================================================================ | |
76 | ||
77 | IMPLEMENT_DYNAMIC_CLASS(wxTGAHandler, wxImageHandler) | |
78 | ||
79 | #if wxUSE_STREAMS | |
80 | ||
81 | // ---------------------------------------------------------------------------- | |
82 | // worker functions | |
83 | // ---------------------------------------------------------------------------- | |
84 | ||
85 | static | |
86 | void FlipTGA(unsigned char* imageData, int width, int height, short pixelSize) | |
87 | { | |
88 | int lineLength = width * pixelSize; | |
89 | unsigned char *line1 = imageData; | |
90 | unsigned char *line2 = &imageData[lineLength * (height - 1)]; | |
91 | ||
92 | unsigned char temp; | |
93 | for ( ; line1 < line2; line2 -= (lineLength * 2)) | |
94 | { | |
95 | for (int index = 0; index < lineLength; line1++, line2++, index++) | |
96 | { | |
97 | temp = *line1; | |
98 | *line1 = *line2; | |
99 | *line2 = temp; | |
100 | } | |
101 | } | |
102 | } | |
103 | ||
104 | // return wxTGA_OK or wxTGA_IOERR | |
105 | static | |
106 | int DecodeRLE(unsigned char* imageData, unsigned long imageSize, | |
107 | short pixelSize, wxInputStream& stream) | |
108 | { | |
109 | unsigned long index = 0; | |
110 | unsigned char current; | |
111 | unsigned int length; | |
112 | unsigned char buf[4]; | |
113 | ||
114 | while (index < imageSize) | |
115 | { | |
116 | int ch = stream.GetC(); | |
117 | if ( ch == wxEOF ) | |
118 | return wxTGA_IOERR; | |
119 | ||
120 | current = ch; | |
121 | ||
122 | // RLE packet. | |
123 | if ( current & 0x80 ) | |
124 | { | |
125 | // Get the run length of the packet. | |
126 | current &= 0x7f; | |
127 | ||
128 | current++; | |
129 | ||
130 | length = current; | |
131 | ||
132 | index += current * pixelSize; | |
133 | ||
134 | // Repeat the pixel length times. | |
135 | if ( !stream.Read(buf, pixelSize) ) | |
136 | return wxTGA_IOERR; | |
137 | ||
138 | for (unsigned int i = 0; i < length; i++) | |
139 | { | |
140 | memcpy(imageData, buf, pixelSize); | |
141 | ||
142 | imageData += pixelSize; | |
143 | } | |
144 | } | |
145 | else // Raw packet. | |
146 | { | |
147 | // Get the run length of the packet. | |
148 | current++; | |
149 | ||
150 | length = current * pixelSize; | |
151 | ||
152 | index += length; | |
153 | ||
154 | // Write the next length pixels directly to the image data. | |
155 | if ( !stream.Read(imageData, length) ) | |
156 | return wxTGA_IOERR; | |
157 | ||
158 | imageData += length; | |
159 | } | |
160 | } | |
161 | ||
162 | return wxTGA_OK; | |
163 | } | |
164 | ||
165 | static | |
166 | int ReadTGA(wxImage* image, wxInputStream& stream) | |
167 | { | |
168 | // Read in the TGA header | |
169 | unsigned char hdr[HDR_SIZE]; | |
170 | stream.Read(hdr, HDR_SIZE); | |
171 | ||
172 | short offset = hdr[HDR_OFFSET] + HDR_SIZE; | |
173 | short colorType = hdr[HDR_COLORTYPE]; | |
174 | short imageType = hdr[HDR_IMAGETYPE]; | |
175 | int paletteLength = hdr[HDR_PALETTELENGTH] + 256 * hdr[HDR_PALETTELENGTH + 1]; | |
176 | int width = (hdr[HDR_WIDTH] + 256 * hdr[HDR_WIDTH + 1]) - | |
177 | (hdr[HDR_XORIGIN] + 256 * hdr[HDR_XORIGIN + 1]); | |
178 | int height = (hdr[HDR_HEIGHT] + 256 * hdr[HDR_HEIGHT + 1]) - | |
179 | (hdr[HDR_YORIGIN] + 256 * hdr[HDR_YORIGIN + 1]); | |
180 | short bpp = hdr[HDR_BPP]; | |
181 | short orientation = hdr[HDR_ORIENTATION] & 0x20; | |
182 | ||
183 | image->Create(width, height); | |
184 | ||
185 | if (!image->Ok()) | |
186 | { | |
187 | return wxTGA_MEMERR; | |
188 | } | |
189 | ||
190 | const short pixelSize = bpp / 8; | |
191 | ||
192 | const unsigned long imageSize = width * height * pixelSize; | |
193 | ||
194 | unsigned char *imageData = (unsigned char* )malloc(imageSize); | |
195 | ||
196 | if (!imageData) | |
197 | { | |
198 | return wxTGA_MEMERR; | |
199 | } | |
200 | ||
201 | wxON_BLOCK_EXIT1(free, imageData); | |
202 | ||
203 | unsigned char *dst = image->GetData(); | |
204 | ||
205 | unsigned char* alpha = NULL; | |
206 | if (bpp == 16 || bpp == 32) | |
207 | { | |
208 | image->SetAlpha(); | |
209 | ||
210 | alpha = image->GetAlpha(); | |
211 | } | |
212 | ||
213 | // Seek from the offset we got from the TGA header. | |
214 | if (stream.SeekI(offset, wxFromStart) == wxInvalidOffset) | |
215 | return wxTGA_INVFORMAT; | |
216 | ||
217 | // Load a palette if we have one. | |
218 | if (colorType == wxTGA_MAPPED) | |
219 | { | |
220 | unsigned char buf[3]; | |
221 | ||
222 | unsigned char* r = new unsigned char[paletteLength]; | |
223 | unsigned char* g = new unsigned char[paletteLength]; | |
224 | unsigned char* b = new unsigned char[paletteLength]; | |
225 | ||
226 | for (int i = 0; i < paletteLength; i++) | |
227 | { | |
228 | stream.Read(buf, 3); | |
229 | ||
230 | r[i] = buf[2]; | |
231 | g[i] = buf[1]; | |
232 | b[i] = buf[0]; | |
233 | } | |
234 | ||
235 | #if wxUSE_PALETTE | |
236 | // Set the palette of the image. | |
237 | image->SetPalette(wxPalette(paletteLength, r, g, b)); | |
238 | #endif // wxUSE_PALETTE | |
239 | ||
240 | delete[] r; | |
241 | delete[] g; | |
242 | delete[] b; | |
243 | } | |
244 | ||
245 | // Handle the various TGA formats we support. | |
246 | ||
247 | switch (imageType) | |
248 | { | |
249 | #if wxUSE_PALETTE | |
250 | // Raw indexed. | |
251 | ||
252 | case 1: | |
253 | { | |
254 | const wxPalette& palette = image->GetPalette(); | |
255 | unsigned char r; | |
256 | unsigned char g; | |
257 | unsigned char b; | |
258 | ||
259 | // No compression read the data directly to imageData. | |
260 | ||
261 | stream.Read(imageData, imageSize); | |
262 | ||
263 | // If orientation == 0, then the image is stored upside down. | |
264 | // We need to store it right side up. | |
265 | ||
266 | if (orientation == 0) | |
267 | { | |
268 | FlipTGA(imageData, width, height, pixelSize); | |
269 | } | |
270 | ||
271 | // Handle the different pixel depths. | |
272 | ||
273 | switch (bpp) | |
274 | { | |
275 | // 8 bpp. | |
276 | ||
277 | case 8: | |
278 | { | |
279 | for (unsigned long index = 0; index < imageSize; index += pixelSize) | |
280 | { | |
281 | palette.GetRGB(imageData[index], &r, &g, &b); | |
282 | ||
283 | *(dst++) = r; | |
284 | *(dst++) = g; | |
285 | *(dst++) = b; | |
286 | } | |
287 | } | |
288 | break; | |
289 | ||
290 | // 16 bpp. | |
291 | ||
292 | case 16: | |
293 | { | |
294 | for (unsigned long index = 0; index < imageSize; index += pixelSize) | |
295 | { | |
296 | palette.GetRGB(imageData[index], &r, &g, &b); | |
297 | ||
298 | *(dst++) = r; | |
299 | *(dst++) = g; | |
300 | *(dst++) = b; | |
301 | *(alpha++) = (imageData[index + 1] & 0x80) ? 0 : 255; | |
302 | } | |
303 | } | |
304 | break; | |
305 | ||
306 | default: | |
307 | return wxTGA_INVFORMAT; | |
308 | } | |
309 | } | |
310 | break; | |
311 | #endif // wxUSE_PALETTE | |
312 | ||
313 | // Raw RGB. | |
314 | ||
315 | case 2: | |
316 | { | |
317 | // No compression read the data directly to imageData. | |
318 | ||
319 | stream.Read(imageData, imageSize); | |
320 | ||
321 | // If orientation == 0, then the image is stored upside down. | |
322 | // We need to store it right side up. | |
323 | ||
324 | if (orientation == 0) | |
325 | { | |
326 | FlipTGA(imageData, width, height, pixelSize); | |
327 | } | |
328 | ||
329 | // Handle the different pixel depths. | |
330 | ||
331 | switch (bpp) | |
332 | { | |
333 | //16 bpp. | |
334 | ||
335 | case 16: | |
336 | { | |
337 | unsigned char temp; | |
338 | ||
339 | for (unsigned long index = 0; index < imageSize; index += pixelSize) | |
340 | { | |
341 | temp = (imageData[index + 1] & 0x7c) << 1; | |
342 | temp |= temp >> 5; | |
343 | *(dst++) = temp; | |
344 | ||
345 | temp = ((imageData[index + 1] & 0x03) << 6) | ((imageData[index] & 0xe0) >> 2); | |
346 | temp |= temp >> 5; | |
347 | *(dst++) = temp; | |
348 | ||
349 | temp = (imageData[index] & 0x1f) << 3; | |
350 | temp |= temp >> 5; | |
351 | *(dst++) = temp; | |
352 | ||
353 | *(alpha++) = (imageData[index + 1] & 0x80) ? 0 : 255; | |
354 | } | |
355 | } | |
356 | break; | |
357 | ||
358 | // 24 bpp. | |
359 | ||
360 | case 24: | |
361 | { | |
362 | for (unsigned long index = 0; index < imageSize; index += pixelSize) | |
363 | { | |
364 | *(dst++) = imageData[index + 2]; | |
365 | *(dst++) = imageData[index + 1]; | |
366 | *(dst++) = imageData[index]; | |
367 | } | |
368 | } | |
369 | break; | |
370 | ||
371 | // 32 bpp. | |
372 | ||
373 | case 32: | |
374 | { | |
375 | for (unsigned long index = 0; index < imageSize; index += pixelSize) | |
376 | { | |
377 | *(dst++) = imageData[index + 2]; | |
378 | *(dst++) = imageData[index + 1]; | |
379 | *(dst++) = imageData[index]; | |
380 | *(alpha++) = imageData[index + 3]; | |
381 | } | |
382 | } | |
383 | break; | |
384 | ||
385 | default: | |
386 | return wxTGA_INVFORMAT; | |
387 | } | |
388 | } | |
389 | break; | |
390 | ||
391 | // Raw grayscale. | |
392 | ||
393 | case 3: | |
394 | { | |
395 | // No compression read the data directly to imageData. | |
396 | ||
397 | stream.Read(imageData, imageSize); | |
398 | ||
399 | // If orientation == 0, then the image is stored upside down. | |
400 | // We need to store it right side up. | |
401 | ||
402 | if (orientation == 0) | |
403 | { | |
404 | FlipTGA(imageData, width, height, pixelSize); | |
405 | } | |
406 | ||
407 | // Handle the different pixel depths. | |
408 | ||
409 | switch (bpp) | |
410 | { | |
411 | // 8 bpp. | |
412 | ||
413 | case 8: | |
414 | { | |
415 | for (unsigned long index = 0; index < imageSize; index += pixelSize) | |
416 | { | |
417 | *(dst++) = imageData[index]; | |
418 | *(dst++) = imageData[index]; | |
419 | *(dst++) = imageData[index]; | |
420 | } | |
421 | } | |
422 | break; | |
423 | ||
424 | // 16 bpp. | |
425 | ||
426 | case 16: | |
427 | { | |
428 | for (unsigned long index = 0; index < imageSize; index += pixelSize) | |
429 | { | |
430 | *(dst++) = imageData[index]; | |
431 | *(dst++) = imageData[index]; | |
432 | *(dst++) = imageData[index]; | |
433 | *(alpha++) = imageData[index + 1]; | |
434 | } | |
435 | } | |
436 | break; | |
437 | ||
438 | default: | |
439 | return wxTGA_INVFORMAT; | |
440 | } | |
441 | } | |
442 | break; | |
443 | ||
444 | #if wxUSE_PALETTE | |
445 | // RLE indexed. | |
446 | ||
447 | case 9: | |
448 | { | |
449 | const wxPalette& palette = image->GetPalette(); | |
450 | unsigned char r; | |
451 | unsigned char g; | |
452 | unsigned char b; | |
453 | ||
454 | // Decode the RLE data. | |
455 | ||
456 | int rc = DecodeRLE(imageData, imageSize, pixelSize, stream); | |
457 | if ( rc != wxTGA_OK ) | |
458 | return rc; | |
459 | ||
460 | // If orientation == 0, then the image is stored upside down. | |
461 | // We need to store it right side up. | |
462 | ||
463 | if (orientation == 0) | |
464 | { | |
465 | FlipTGA(imageData, width, height, pixelSize); | |
466 | } | |
467 | ||
468 | // Handle the different pixel depths. | |
469 | ||
470 | switch (bpp) | |
471 | { | |
472 | // 8 bpp. | |
473 | ||
474 | case 8: | |
475 | { | |
476 | for (unsigned long index = 0; index < imageSize; index += pixelSize) | |
477 | { | |
478 | palette.GetRGB(imageData[index], &r, &g, &b); | |
479 | ||
480 | *(dst++) = r; | |
481 | *(dst++) = g; | |
482 | *(dst++) = b; | |
483 | } | |
484 | } | |
485 | break; | |
486 | ||
487 | // 16 bpp. | |
488 | ||
489 | case 16: | |
490 | { | |
491 | for (unsigned long index = 0; index < imageSize; index += pixelSize) | |
492 | { | |
493 | palette.GetRGB(imageData[index], &r, &g, &b); | |
494 | ||
495 | *(dst++) = r; | |
496 | *(dst++) = g; | |
497 | *(dst++) = b; | |
498 | *(alpha++) = (imageData[index + 1] & 0x80) ? 0 : 255; | |
499 | } | |
500 | } | |
501 | break; | |
502 | ||
503 | default: | |
504 | return wxTGA_INVFORMAT; | |
505 | } | |
506 | } | |
507 | break; | |
508 | #endif // wxUSE_PALETTE | |
509 | ||
510 | // RLE RGB. | |
511 | ||
512 | case 10: | |
513 | { | |
514 | // Decode the RLE data. | |
515 | ||
516 | int rc = DecodeRLE(imageData, imageSize, pixelSize, stream); | |
517 | if ( rc != wxTGA_OK ) | |
518 | return rc; | |
519 | ||
520 | // If orientation == 0, then the image is stored upside down. | |
521 | // We need to store it right side up. | |
522 | ||
523 | if (orientation == 0) | |
524 | { | |
525 | FlipTGA(imageData, width, height, pixelSize); | |
526 | } | |
527 | ||
528 | // Handle the different pixel depths. | |
529 | ||
530 | switch (bpp) | |
531 | { | |
532 | //16 bpp. | |
533 | ||
534 | case 16: | |
535 | { | |
536 | unsigned char temp; | |
537 | ||
538 | for (unsigned long index = 0; index < imageSize; index += pixelSize) | |
539 | { | |
540 | temp = (imageData[index + 1] & 0x7c) << 1; | |
541 | temp |= temp >> 5; | |
542 | *(dst++) = temp; | |
543 | ||
544 | temp = ((imageData[index + 1] & 0x03) << 6) | ((imageData[index] & 0xe0) >> 2); | |
545 | temp |= temp >> 5; | |
546 | *(dst++) = temp; | |
547 | ||
548 | temp = (imageData[index] & 0x1f) << 3; | |
549 | temp |= temp >> 5; | |
550 | *(dst++) = temp; | |
551 | ||
552 | *(alpha++) = (imageData[index + 1] & 0x80) ? 0 : 255; | |
553 | } | |
554 | } | |
555 | break; | |
556 | ||
557 | // 24 bpp. | |
558 | ||
559 | case 24: | |
560 | { | |
561 | for (unsigned long index = 0; index < imageSize; index += pixelSize) | |
562 | { | |
563 | *(dst++) = imageData[index + 2]; | |
564 | *(dst++) = imageData[index + 1]; | |
565 | *(dst++) = imageData[index]; | |
566 | } | |
567 | } | |
568 | break; | |
569 | ||
570 | // 32 bpp. | |
571 | ||
572 | case 32: | |
573 | { | |
574 | for (unsigned long index = 0; index < imageSize; index += pixelSize) | |
575 | { | |
576 | *(dst++) = imageData[index + 2]; | |
577 | *(dst++) = imageData[index + 1]; | |
578 | *(dst++) = imageData[index]; | |
579 | *(alpha++) = imageData[index + 3]; | |
580 | } | |
581 | } | |
582 | break; | |
583 | ||
584 | default: | |
585 | return wxTGA_INVFORMAT; | |
586 | } | |
587 | } | |
588 | break; | |
589 | ||
590 | // RLE grayscale. | |
591 | ||
592 | case 11: | |
593 | { | |
594 | // Decode the RLE data. | |
595 | ||
596 | int rc = DecodeRLE(imageData, imageSize, pixelSize, stream); | |
597 | if ( rc != wxTGA_OK ) | |
598 | return rc; | |
599 | ||
600 | // If orientation == 0, then the image is stored upside down. | |
601 | // We need to store it right side up. | |
602 | ||
603 | if (orientation == 0) | |
604 | { | |
605 | FlipTGA(imageData, width, height, pixelSize); | |
606 | } | |
607 | ||
608 | // Handle the different pixel depths. | |
609 | ||
610 | switch (bpp) | |
611 | { | |
612 | // 8 bpp. | |
613 | ||
614 | case 8: | |
615 | { | |
616 | for (unsigned long index = 0; index < imageSize; index += pixelSize) | |
617 | { | |
618 | *(dst++) = imageData[index]; | |
619 | *(dst++) = imageData[index]; | |
620 | *(dst++) = imageData[index]; | |
621 | } | |
622 | } | |
623 | break; | |
624 | ||
625 | // 16 bpp. | |
626 | ||
627 | case 16: | |
628 | { | |
629 | for (unsigned long index = 0; index < imageSize; index += pixelSize) | |
630 | { | |
631 | *(dst++) = imageData[index]; | |
632 | *(dst++) = imageData[index]; | |
633 | *(dst++) = imageData[index]; | |
634 | *(alpha++) = imageData[index + 1]; | |
635 | } | |
636 | } | |
637 | break; | |
638 | ||
639 | default: | |
640 | return wxTGA_INVFORMAT; | |
641 | } | |
642 | } | |
643 | break; | |
644 | ||
645 | default: | |
646 | return wxTGA_INVFORMAT; | |
647 | } | |
648 | ||
649 | return wxTGA_OK; | |
650 | } | |
651 | ||
652 | static | |
653 | int SaveTGA(wxImage* WXUNUSED(image), wxOutputStream& WXUNUSED(stream)) | |
654 | { | |
655 | wxLogError(wxT("Saving in TGA format is not implemented.")); | |
656 | ||
657 | return wxTGA_OK; | |
658 | } | |
659 | ||
660 | // ---------------------------------------------------------------------------- | |
661 | // wxTGAHandler | |
662 | // ---------------------------------------------------------------------------- | |
663 | ||
664 | bool wxTGAHandler::LoadFile(wxImage* image, | |
665 | wxInputStream& stream, | |
666 | bool verbose, | |
667 | int WXUNUSED(index)) | |
668 | { | |
669 | if ( !CanRead(stream) ) | |
670 | { | |
671 | if ( verbose ) | |
672 | wxLogError(wxT("TGA: this is not a TGA file.")); | |
673 | ||
674 | return false; | |
675 | } | |
676 | ||
677 | image->Destroy(); | |
678 | ||
679 | int error = ReadTGA(image, stream); | |
680 | if ( error != wxTGA_OK ) | |
681 | { | |
682 | if ( verbose ) | |
683 | { | |
684 | switch ( error ) | |
685 | { | |
686 | case wxTGA_INVFORMAT: | |
687 | wxLogError(wxT("TGA: image format unsupported.")); | |
688 | break; | |
689 | ||
690 | case wxTGA_MEMERR: | |
691 | wxLogError(wxT("TGA: couldn't allocate memory.")); | |
692 | break; | |
693 | ||
694 | case wxTGA_IOERR: | |
695 | wxLogError(wxT("TGA: couldn't read image data.")); | |
696 | break; | |
697 | ||
698 | default: | |
699 | wxLogError(wxT("TGA: unknown error!")); | |
700 | } | |
701 | } | |
702 | ||
703 | image->Destroy(); | |
704 | ||
705 | return false; | |
706 | } | |
707 | ||
708 | return true; | |
709 | } | |
710 | ||
711 | bool wxTGAHandler::SaveFile(wxImage* image, wxOutputStream& stream, bool verbose) | |
712 | { | |
713 | int error = SaveTGA(image, stream); | |
714 | ||
715 | if ( error != wxTGA_OK ) | |
716 | { | |
717 | if ( verbose ) | |
718 | { | |
719 | switch ( error ) | |
720 | { | |
721 | case wxTGA_INVFORMAT: | |
722 | wxLogError(wxT("TGA: invalid image.")); | |
723 | break; | |
724 | ||
725 | case wxTGA_MEMERR: | |
726 | wxLogError(wxT("TGA: couldn't allocate memory.")); | |
727 | break; | |
728 | ||
729 | default: | |
730 | wxLogError(wxT("TGA: unknown error!")); | |
731 | } | |
732 | } | |
733 | ||
734 | return false; | |
735 | } | |
736 | ||
737 | return true; | |
738 | } | |
739 | ||
740 | bool wxTGAHandler::DoCanRead(wxInputStream& stream) | |
741 | { | |
742 | // read the fixed-size TGA headers | |
743 | unsigned char hdr[HDR_SIZE]; | |
744 | stream.Read(hdr, HDR_SIZE); | |
745 | ||
746 | // Check wether we can read the file or not. | |
747 | ||
748 | short colorType = hdr[HDR_COLORTYPE]; | |
749 | if ( colorType != wxTGA_UNMAPPED && colorType != wxTGA_MAPPED ) | |
750 | { | |
751 | return false; | |
752 | } | |
753 | ||
754 | short imageType = hdr[HDR_IMAGETYPE]; | |
755 | if ( imageType == 0 || imageType == 32 || imageType == 33 ) | |
756 | { | |
757 | return false; | |
758 | } | |
759 | ||
760 | short bpp = hdr[HDR_BPP]; | |
761 | if ( bpp != 8 && bpp != 16 && bpp != 24 && bpp != 32 ) | |
762 | { | |
763 | return false; | |
764 | } | |
765 | ||
766 | return true; | |
767 | } | |
768 | ||
769 | #endif // wxUSE_STREAMS | |
770 | ||
771 | #endif // wxUSE_IMAGE && wxUSE_TGA |